My 5.0 LX died... help!

[exc911ence]

So here's the deal: I have my 89 5.0 LX for sale and let a guy take it out for test drive this afternoon. He had it out for about 15 minutes when for no reason, the car died. The engine stopped and the gauges went dead. Also, the heater blower, radio, 4 way flashers, turn signals, wipers/washer and rear defroster are dead too. The car still has headlights, dash lights, etc but the ignition switch doesn't bring the warning lights on and the starter motor isn't getting juice when you turn the key. If you jump the starter relay, the engine turns over fine but won't light up. The fuel level is was pretty low though, would the car running out of gas kill the electrics in the car?

Anyone know what could be the problem? The guy is still interested in the car and I need to get it up and running soon. The irony is that the car has never, ever let me down before and I drive it everyday (including this morning!). Maybe it doesn't want to be sold...

 

[Mustang5L5]

Check your battery connections and starter solenoid. Make sure everything is corrosion free and nice and tight

 

[chobracobra]

its deffinatly a sign dude...dont sell it!

 

[seijirou]

pull the covers off your steering column. When the column is exposed you'll see that the key cylinder sits forward of a rectangular block, with a plug that plugs in from underneath. This block is your ignition and distributes power for key on, start, ect. It's only pressed onto your column by the friction of small teeth on the column. This thing can wiggle lose, and then you loose all your ignition power ect. You can wiggle the plug and tell very easily if it's loose or not. Turn the key to on, and then push up on the plug and see if you get your power back. If so, you can replace it, or, get a long ziptie and ziptie it up tight around the column again.
When wiggling, be careful not to pull down, you don't want this thing coming off the column as it contains bearings and springs that will fall out all over the place, they are a pain to find and put back together correctly.

 

[exc911ence]

Thanks for the quick replies!

I tried the column switch as you said but it's tightly attached still. I unplugged the connector and reattached it but still nothing. I can't find any wires burnt, connectors loose and fuses blown under the dash. Man, this is pissing me off. I don't get why I have power to some dash functions and none anywhere else. Is there a 2nd fuse box I should be looking for? Maybe a fried fusable link? Any chance the control module packed it in? What about the inertia switch for the fuel system... does it tie into other electrical systems like the center console? The car has started and run flawlessly forever... why now???

I don't think the electric fuel pump is working either. I have a fuel pressure gauge mounted in the engine compartment but it's registering nothing, even when I crank the engine over by jumping the relay.

 

[seijirou]

Unfortunatly no, there isn't a second fuse panel. And the inertia switch is only hooked up to the fuel pump.

It could be a fuseable link. Most of them if not all are near your Starter Solenoid on your driver's side front strut tower.

If you have a volt meter test for power at that ignition switch aswell. Sometimes they fry internally, but I've only rarely ever heard of it.

I'll attach some diagrams that may help.

 

[exc911ence]

Great diagrams! Much better than the tiny ones in the Haynes manual. I'm getting a suspician that the ignition switch might be at fault. Going by the diagram, most of what's not functioning routes through that switch and the other things that are working, don't get power via the ignition switch. There are a couple of exceptions though: I'm getting power to the interior lights which go through the switch yet I don't have a heater blower even though it's in a separate circuit.

The mystery continues...

 

[HISSIN50]

the switch was a recall item on many stangs. call and check - you might get one for free. otherwise, they are cheap.

good luck.

 

[exc911ence]

Just grabbed one from a 1990 off a buddy. I'll be transplanting it and troubleshooting the system in the morning. Thanks for the "good luck", I'll be needing it!

 

[exc911ence]

IT'S ALIVE!!!! Turns out that the wire from the starter relay to the fusable link burnt through... go figure. I though it was the link that was supposed to fry first! What happened was that the P/O had a ton of stereo wires run throughout the car and one was directly plugged into the fuse box without a fuse. The other end of that wire was loose under the console and shorted out while the guy was driving the car. So, I gutted all of the stereo crap, replaced the wire to the fusable link and voila, the car runs. Life is good... the thing's still for sale but I haven't told it yet.

 

[HISSIN50]

nice work and good luck with the next phase (selling it).

 

[seijirou]

Excelling, glad to hear it got sorted out